The objective of this study was to show the feasibility of performing ASL based high resolution perfusion imaging in the mouse brain at 9.4 Tesla. In this work we applied pCASL with phase optimization technique at the labeling plane to minimize the effect of B0 inhomogenity . We used fcFLASH based technique to measure the labeling efficiency of pCASL sequence and compared the labeling efficiency with FAIR ASL in mouse brain. Based on our results, with the proposed method of phase optimization, labelling slice can be place away from the iso-center of the magnet. This will allow us to place the imaging slice at the isocenter, which has showed significant improvement in the image quality of the mouse brain at ultra-high field strengths.